I thought you were keeping the kittens indoors. That's where they need to be.
Can you take the kittens to a no-kill shelter where they can be properly fed, receive medical care, and get adopted? If you are not home much, and the mom cat is not feeding them much, they need to be at a shelter where they can receive proper care and feeding at all times.
Then you can focus on getting the mom cat spayed asap.
Can you tell us where you are located - city and state, and we will find a shelter for you.
Can you take the kittens to a no-kill shelter where they can be properly fed, receive medical care, and get adopted? If you are not home much, and the mom cat is not feeding them much, they need to be at a shelter where they can receive proper care and feeding at all times.
Then you can focus on getting the mom cat spayed asap.
Can you tell us where you are located - city and state, and we will find a shelter for you.